Hydraulic lash adjuster



June 27, 1939. P. E. wHALEN HYDRAULIC LASH ADJUSTER Filed July 2, 1937INVENTOR Ffz/A Wf//f/K QM-LM m4# r i# j ATTORNEYS.

Patented June 21, 193e UNITED STATES PATENT OFFICE 20 Claims.

This invention relates to an hydraulic clearance compensator which isparticularly applicable to the valve operating mechanisms of internalcombustion engines. One object of the present inven- 5 tion is toprovide an hydraulic compensator which not only takes up backlash in thetrain of parts operating the valves of an internal combustion engine,but also compensates for expansion of these parts as they become heatedunder engine l operation.

Another object of the invention is to provide a compensator which may beadded as an accessory to cars already built and having adjustable valvetappets of the conventional type.

l Other objects of the invention and the features by which these objectsare attained will be apparent from the accompanying drawings and thefollowing specification and claims:

Fig. 1 is an elevational view partly in section of a portion of thevalve operating mechanism to which a preferred form of the invention hasbeen applied. Fig. 2 is a sectional view on an enlarged scale of partsshown in Fig. l. Fig. 3 is a sectional view taken substantially on theline 2 2 of Fig. 2.

Fig. 4 is a similar sectional view taken on the same line with the partsin a different position. Fig. 5

is a perspective view of a resilient cylinder forming one of thefeatures of the invention. Fig. 6 is an elevational view partly insection showing an alternative form of the invention.

In Fig. l of the drawing there is shown, by way of illustration, apreferred form of the invention as applied to a splash lubricated valvemechanism. A cam ill which may be the conventional form of valveoperating cam, engages a tappet il which may also be of conventionalform and which carries an adjusting screw I2 locked in position by alock nut i3. The tappet li is vertically slidable in a guide il carriedby the engine body. A valve operating member I6, which may be the stemof the valve itself in case of an L-head engine. or the stem operatingthe valve rockers in the case of an overhead valve engine, is providedwith the usual split keeper i1 engaging grooves i2 formed thereon. Aspring seat I9 engages the conical outer surface of the keeper i1 andreceives the lower end of a valve spring 2li which serves to close thevalve in a conventional manner.

The valve operating member or stem i6 rests upon the upper surface of ametallic cap 2l which in turn rests upon the upper surface of a cylinder22 formed of a resilient material and snugly iitting a substantiallycylindrical bore 22 in the head of the adjusting screw I2. The cylinder22 is prefer- 55 ably formed of a material commercially known as Dupreneor Neoprene, which is a rubber-like substance having the resilientcharacteristics of rubber but which is not deteriorated by contact withoil. The resilient cylinder 22 is provided with a central opening 24which receives a down- 5 wardly projecting portion 2B of the cap 2l.Said portion 25 normally does not extend the full distance to the bottomof the cylinder 22 and thus leaves a cavity which may be contracted andenlarged by the compression and release of the 10 cylinder 22 aspressure is applied to and released from the cap 2i.

'I'he cap 2i is provided with a central vertical passage 26 extendingupwardly from the bottom of the cap but terminating short of the topthere- 16 of. The passage 26 is intersected by a horizontal passage 2lextending to the rim of the cap 2i and by a second passage 28 extendinghorizontally through the lower portion 25 of the cap. A valve pin 29 ofsmaller diameter than the passage 28 is 2o carried therein. The upperedge of the bore 22 is provided with a cut recess 2li permitting freecommunication between the passage 2l and the exterior of the adjustingscrew l2.

In the operation of the form of the invention 25 just described. it isassumed that the valve operating mechanism is suillciently supplied withoil by a splash system so that a quantity of oil may collect in theupper portion of the bore 22 above the cap 2i and particularly in thegroove 2li. In 30 the upward movement oi' the valve mechanism thepressure of the cam is transmitted through the cap 2l to the stem I6 andthe cap 2i is. therefore, forced against the resilient cylinder 22 andcontracts the central cavity therein. In the down- 35 ward movement, ifthere is any backlash present in the mechanism. the pressure is releasedand the central cavity may expand. In this expansion, a small amount ofoil is drawn in from the upper part of the bore 22 through the recess30, the 40 passage 21, the upper part of the passage 26 and through thepassage 28 to the interior of the cylinder 22. In this downwardmovement, the valve pin 29 is in the position shown in Fig. 3 in whichoil may freely flow from the passage 26 45 along the top of the pin 29and out at each end of the passage 2B.

On the next upward stroke of the mechanism. the central cavity is againcompressed and oil contained therein is forced upwardly through thelower part of the passage 28 to hold the pin 29 against the uppersurface of passage 28, as shown in Fig. 4. Since the pin is of smallerdiameter than the passage 2li, the upper portion of passage 26 is notentirely closed. A space per- 55 mitting escape oi' a .very small amountof oil is provided at Il. However, the passage at 8i is so restrictedthat only a small part oi the oil may escape as compared to the amountwhich may enter on the downward stroke of the mechanism Repeated upwardand downward strokes. therefore. serve to pump a suillcient quantity ofincompressible oil into the central cavity to maintain a uniform contactbetween the cap 2l and the stem it and thus to take up whatever backlashthere may be in the mechanism. If, however, the tappet Il, stem II andother parts expand due to heating, the pressure on the cap 2| isincreased and this pressure may be relieved by the escape of the smallamount of oil through the opening at Il since the pressure will besufilciently great to restrict the inilow of oil on the down stroke.Thus, the compensator adjusts not only for backlash but for excessivepressure due to expansion of the parts. By the use of pins 2! ofappropriate diameter, the proper relation between inilow and outnow maybe obtained for any given type of valve gear.

In the pumping action it will be seen that the resilient cylinder 22, lnaddition to its use in providing a central cavity of variable size.serves also to seal the cavity against undesired inow or outilow of oileven though there may be considerable clearance between the outer edgesof the cap 2i and the bore Il. Thus, the relatively unrestricted inilowof oil when required to take up backlash and the relatively restrictedoutnow of oil is controlled entirely by the action oi' the valve pin 22.

It will also be apparent that all of the parts described which are notfound in the conventional valve mechanism are contained within the headof the adjusting screw il. In order to ilt the invention to an enginealready built, it is only necessary to replace the standard adjustingscrew with one bored out as described and fitted with the internal parts2i, 22, etc. It will also be apparent that a relatively small amount ofoil is required for operation oi' the device.

In Fig. 6, there is shown a form of the invention applied to a pressurelubricated valve mechanism. In this drawing parts having the sameconstruction and function as those in Fig. l are indicated by the samereference numbers. There are also shown a tappet iii, adjusting screwIII, tappet guide lil and cap III, each of slightly differentconstruction than the corresponding parts of Fig. 1.

Oil under pressure is supplied to the guide lil from the centrallubricating system of the engine by a passage 3l to a counterbore I2surrounding the tappet iii. A passage u within the tappet communicateswith the counterbore and conducts the oil to the central threaded cavityof the tappet. The adjusting screw ii2 is provided with a recess incontaining the resilient cylinder 22 and cap III and communicating withthe cavity I3 by a passage II, the upper end oi' which is closed by aball check valve SI of conventional form permitting inilow of oil to therecess i2l but preventing outflow therefrom.

In the operation of this form of the invention the alternate contractionand expansion of the central cavity of the cylinder 22 results in apumping action as before which lls said cavity with incompressible oilunder suiilcient pressure to insure that there will be no backlash inthe mechanism. If it is desired to adapt this form of the invention toadjust for expansion of the parts, means are provided for the escape ofan aisance lil construed as limiting the scope thereof to these exactforms. Many variations may be made by those skilled in the art withoutdeparting from the invention as denned by the appended claims.

The invention claimed is:

i 1. In combination with a valve tappet and a valve operating member, anadjusting screw carried by said valve tappet and having a cavity formedin the head thereof, a hollow cylinder oi elastic material seated insaid cavity. a substantially non-elastic closure for said cylinder. saidclosure engaging said valve operating member, and means for supplying asubstantially noncompressible uid to the interior of said cylinder.

2. In combination with` a valve tappet and a valve operating member, anadjusting screw carried by said valve tappet and having a substantiallycylindrical bore formed in the head thereof. a hollow cylinder ofelastic material snugly seated in said bore, a closure for saidcylinder, said closure engaging said valve operating member, and meansfor supplying a substantially noncompressible iluid to the interior ofsaid cylinder.

3. In combination with a valve tappet and a valve operating member, anadjusting screw carried by said valve tappet and having a substantiallycylindrical bore formed in the head thereof. a hollow cylinder orelastic material snugly seated in said bore. the lower end of saidcylinder resting on the base of said bore, a closure for said cylinder,resting on the upper end of the same and engaging said valve operatingmember, whereby pressure exerted on said closure tends to compress saidcylinder and to diminish the interior volume thereof, and means forsupplying a u substantially non-compressible fluid to the interior ofsaid cylinder.

4. In combination with a valve tappet and a valve operating member, anadjusting screw carried by said valve tappet and having a substantiallycylindrical bore formed in the head thereof, a hollow cylinder ofelastic material snugly seated in said bore, the lower end of saidcylinder resting on the base oi said bore, a closure for said cylinder,resting on the upper end of the same and engaging said valve operatingmember. whereby alternate exertion and release of pressure on saidclosure tends alternately to diminish and increase the interior volumeof said cylinder, and valve means movable between an opened conditionand a partially opened condition. said valve means being automaticallyopened during increase of the volume of said cylinder for now of asubstantially non-compressible fluid to the interior of,

said cylinder and being partially opened during u decrease of the volumeoi said cylinder for escape of said iluid from said cylinder at agreatly reduced rate.

5. In combination with a valve tappet and a valve operating member. anadjusting screw carried by said valve tappet and having a substantiallycylindrical bore formed in the head thereof, a hollow cylinder ofelastic material seated in said bore. the lower end of said cylinderresting on the base oi' said bore. a closure for said cylinder,

resting on the upper end oi the same and engaging said valve operatingmember. whereby alternate exertion and release o! pressure on saidclosure tends alternately to diminish and increase the interior volumeof said cylinder, and valve means in said closure opened during increaseof the volume oi' said cylinder for now ot a substantiallynon-compressible fluid to the interior of said cylinder.

6. In combination with a valve tappet and a valve operating member, anadjusting screw carried 'by said valve tappet and having a substantiallycylindrical bore formed in the head thereof, a hollow cylinder ofelastic material seated in said bore, the lower end of said cylinderresting on the base of said bore, a closure for said cylinder, restingon the upper end oi' the same and engaging said valve operating member,whereby alternate exertion and release of pressure on said cloao suretends alternately to diminish and increase the interior volume of saidcylinder, and valve means in said closure movable between an openedcondition and a partially opened condition, said valve means beingautomatically opened during increase of the volume of said cylinder forilow oi a substantially non-compressible iiuid to the interior of saidcylinder and being partially opened during decrease of the volume cisaid cylinder for escape of said fluid from said cylinder at a greatlyreduced rate.

7. In an hydraulic lash adjuster. the combination of a member having asubstantially cylindrical bore formed therein, a hollow cylinder oielastic material seated in said bore, a substantially non-elasticclosure for said cylinder, and means for supplying a substantiallynon-compressible tluid to the interior of said cylinder.

8. In an hydraulic lash adjuster, the combination o1' a member having asubstantially cylindrical bore formed therein, a hollow cylinder oi'elastic material snugly seated in said bore, a closure for saidcylinder, and means for supplying a substantially non-compressible uidto the interior of said cylinder.

9. In an hydraulic lash adjuster, the combination oi' a member having asubstantially cylindrical bore formed therein, a hollow cylinder oi'elastic material iltted in said bore, one end oi said cylinder engagingthe inner end of said bore, a closure for said cylinder engaging theopposite end thereof whereby pressure exerted on said closure tends tocompress said cylinder and to diminish the interior volume thereof, andmeans for supplying a substantially non-compressible fluid to theinterior of said cylinder.

l0. In an hydraulic lash adjuster. the combination of a member having asubstantially cylindrical bore formed therein, a hollow cylinder oielastic material fitted in said bore, one end oi said cylinder engagingthe inner end of said bore, a closure for said cylinder enaging theopposite end thereof whereby alternate exertion and release of pressureon said closure tends alternately to diminish and increase the interiorvolume of said cylinder, and valve means movable between an openedcondition and a partially opened condition, said valve means beingautomatically opened during increase oi' the volume of said cylinder fordow of a substantially non-compressible uid to the interior oi' saidcylinder and being partially opened during decrease of the volume o1said cylinder for escape of said iluid from said cylinder at a greatlyreduced rate.

l1. In an hydraulic lash adjuster, the comblnation of a member having asubstantially cylindrical bore formed therein, a hollow cylinder ofelastic material iitted In said bore, one end oi' said cylinder engagingthe inner end oi' said bore, a closure for said cylinder enlasins theopposite end oi the `same whereby alternate exertion and release ofpressure on said closure tends alternately to diminish and increase theinterior volume of said cylinder, and valve means in said closure openedduring increase ot the volume of said cylinder for ow of a substantiallynon-comprensible duid to the interior of said cylinder.

i2. In an hydraulic lash adjuster, the combination oi' a member having asubstantially cylindrical bore formed therein, a hollow cylinder ofelastic material fitted in said bore, the lower end of said cylinderensaslns the inner end oi said bore, a closure for said cylinderengaging the opposite end oi' the same whereby alternate exertion andrelease of pressure on said closure tends alternately to diminish andincrease the interior volume of said cylinder, and valve means in saidclosure movable between an opened condition and a partially openedcondition, said valve means being automatically opened during increaseof the volume oi said cylinder for ilow oi' a substantiallynon-compressible iluid to the interior of said cylinder and beingpartially opened during decrease of the volume of said cylinder forescape of said iiuid from said cylinder at a greatly reduced rate.

13. In an hydraulic lash adjuster, the combination of a member having arecess formed therein, a hollow cylinder of elastic material seated insaid recess, a cap seated on said cylinder, said cylinder providingsealing means preventing escape of liquid from the interior thereofbetween said recessed member and said cap, and means for introducing aliquid into the interior of said cylinder.

14. In an hydraulic lash adjuster, the combination of a member having arecess formed therein, a hollow cylinder of elastic material seated insaid recess, and a cap seated on said cylinder, said cylinder serving toresiliently resist relative movement between said recessed member andsaid cap, and means for introducing a liquid into the interior oi' saidcylinder.

15. In an hydraulic lash adjuster, the combination of a member formed ofresilient material and having an internal cavity, a pair oi relativelymovable members substantially enclosing said resilient member andadapted by their relative movement to alternately expand and contractsaid internal cavity, one oi said members having a passage leading tosaid internal cavity for introduction of a uid thereto, and a valve insaid passage movable between an opened and a partially closed condition,said valve being opened during expansion of said cavity for relativelyfree inflow oi' fluid thereto and partially closed during contractionthereof for relatively restricted outflow therefrom.

16. In an hydraulic lash adjuster, the combination of a pair oirelatively movable members defining a compression chamber, sealing meansfor said chamberl one oi said members having a passage admitting uid tosaid chamber, and a valve in said passage movable between an opened anda partially closed condition, said valve being opened for relativelyfree tlow during inflow of fluid thereto and partially closed forrelatively restricted ow during outilow therefrom.

1'?. In an hydraulic lash adjuster, the combination o1' a pair oi'relatively movable members denning a compression chamber, sealing meansfor said chamber, one oi said members having a passage communicating'with said chamber and a second passage admitting fluid to the ilrstpassage, and s valve pin in said first passage of small-I er diameterthan said passage. movable in one direction by compression oi saidchamber to partially close the intersection o! said passages and movablein the other direction by expansion of said chamber to free saidintersection for passage oi duid into said chamber.

18. In an hydraulic lash adjuster, the combination of a member having arecess formed therein. a cap relatively movable within said recess,resilient means retaining said cap in spaced relation to the bottom oi'said recess to form a compression chamber therein, said cap having apassage therein communicating at both ends with said chamber and asecond passage intersecting said iirst passage and admitting fluidthereto, and a valve pin in said nrst e of smaller diameter than saidpassage, movable in one direction by compression oi said chamber topartially close the intersection of said passages and movable in theother direction by expansion of said chamber to free said intersectionfor passage oi iiuid into said chamber.

19. In an hydraulic lash adjuster. the combination of a member having asubstantially cylin- :50 drlcal bore formed therein, a hollow cylinderoi aisance elastically compressible material seated in said bore, a capseated on said cylinder and 'forming with the interior thereof a closedcompression chamber, said cap having a passage therein communicating atboth ends with said chamber and a second a intersecting said ilrstpassage and admitting iluid thereto, and a valve pin in said firstpassage ot smaller diameter than said e, movable in one direction bycompression of said chamber to partially close the intersection of saidpassages and movable in the other direction by expansion of said chamberto free said intersection for passage o! iluidinto said chamber.

20. In an hydraulic lash adjuster, the combination of a pair ofrelatively movable members deilning a compression chamber, sealing meansfor said chamber, at least one of said members being provided withpassages admitting iiow of iluid to and from said chamberl and valvemeans adapted to open said passages for relatively free flow of iluidand to partially close the same for relatively restricted ilow, saidvalve means opening said passages for relatively free ini-low of fluidthereto during expansion of said chamber and partially closing saidpassages for relatively restricted outflow therefrom during compressionof said chamber.

PAUL E. WHALEN.

DISCLAIMER 2,163,969.Paul E'. Whalen, Bedford, Ind. HYDRAULIC LAsnAnmsm. Patent dated June 27, 1939. Disclaimer filed June 16, 1941, bythe patentes.

Hereby enters this disclaimer to claims 16 and 20 of said specification.

[Oficial Gazette July 8, 1.941.]

denning a compression chamber, sealing means for said chamber, one oisaid members having a passage communicating 'with said chamber and asecond passage admitting fluid to the ilrst passage, and s valve pin insaid first passage of small-I er diameter than said passage. movable inone direction by compression oi said chamber to partially close theintersection o! said passages and movable in the other direction byexpansion of said chamber to free said intersection for passage oi duidinto said chamber.

18. In an hydraulic lash adjuster, the combination of a member having arecess formed therein. a cap relatively movable within said recess,resilient means retaining said cap in spaced relation to the bottom oi'said recess to form a compression chamber therein, said cap having apassage therein communicating at both ends with said chamber and asecond passage intersecting said iirst passage and admitting fluidthereto, and a valve pin in said nrst e of smaller diameter than saidpassage, movable in one direction by compression oi said chamber topartially close the intersection of said passages and movable in theother direction by expansion of said chamber to free said intersectionfor passage oi iiuid into said chamber.

19. In an hydraulic lash adjuster. the combination of a member having asubstantially cylindrical bore formed therein, a hollow cylinder oiaisance elastically compressible material seated in said bore, a capseated on said cylinder and 'forming with the interior thereof a closedcompression chamber, said cap having a passage therein communicating atboth ends with said chamber and a second a intersecting said ilrstpassage and admitting iluid thereto, and a valve pin in said firstpassage ot smaller diameter than said e, movable in one direction bycompression of said chamber to partially close the intersection of saidpassages and movable in the other direction by expansion of said chamberto free said intersection for passage o! iluidinto said chamber.

20. In an hydraulic lash adjuster, the combination of a pair ofrelatively movable members deilning a compression chamber, sealing meansfor said chamber, at least one of said members being provided withpassages admitting iiow of iluid to and from said chamberl and valvemeans adapted to open said passages for relatively free flow of iluidand to partially close the same for relatively restricted ilow, saidvalve means opening said passages for relatively free ini-low of fluidthereto during expansion of said chamber and partially closing saidpassages for relatively restricted outflow therefrom during compressionof said chamber.

PAUL E. WHALEN.

DISCLAIMER 2,163,969.Paul E'. Whalen, Bedford, Ind. HYDRAULIC LAsnAnmsm. Patent dated June 27, 1939. Disclaimer filed June 16, 1941, bythe patentes.

Hereby enters this disclaimer to claims 16 and 20 of said specification.

[Oficial Gazette July 8, 1.941.]

